What I would like to do is extend the life of my rig by maybe 6 to 9 more months without changing my mobo and doing a whole new rebuild. Is there any processor upgrade that would be cost effective at this point? Would adding another gig of memory be worth the cost? What about going with a top of the line AGP 8x video card? Should I just wait a few months and build a new rig?

Theoretically it's never "worth it" to build/upgrade a gaming rig since these class of pc's depreciate the fastest. But it's essentially a hobby and most hobbies are not really "worth it" monetarily, but worth it in the aspect of pleasure or enjoyment, so it's a moot point.

If I were in your situation, currently if some game that you play isn't performing well in some aspect and upgrading whatever will fix it, do it. If you're upgrading for the sake of upgrading, wait and save your cash.

AMD cpu pricess are supposed to drop on the 24th? And DDR2 prices are supposed to go up? But that shouldn't matter since most AMD chipsets only use DDR? Not sure, don't keep up with this things like I used to... Wasn't "worth it" anymore. heh

Your upgrade options for Socket 754 are limited; that said, if you want to keep the computer for some purpose or another (not necessarily gaming, perhaps as a server) for the indefinite future, it would be better to buy the best CPU your motherboard can handle before that CPU gets to be too hard to find.

If you want to keep using your computer as a gaming machine, the best thing you can do for it is to keep the video card as up-to-date as possible. While games do lean on the CPU pretty heavily for their physics and their AI, the video demands of modern games far outweigh all other considerations, except (sometimes) for memory.

Speaking of which, you have a gigabyte of memory; do you have room for 2GB? If so, you might as well get it; DDR is cheap these days and if you have enough RAM you can turn off the swapfile on your hard drive, which will free up the hard drive's data transfer capacity for more important things like loading game levels and whatnot.